Pest destroying emulsion



Patented Mar. 19, 1940 PEST DESTROYING EMULSION Richard Neu, Dessau-Rosslau, Anhalt, Germany,

assignor to Deutsche Hydrierwerke Aktiengesellschaft, Berlin-Charlottenburg, Germany,

a corporation of Germany No Drawing. Application June 26, 1936, Serial No. 87,465. In Germany June 26, 1935 1 Claim.

As it is known, the rotenone has the property of dissolving in aliphatic hydrocarbons but only to a little degree, so that solutions made in this way are unfit'for the combating of vermin. In aromatic hydrocarbons, it is true, the rotenone is easily soluble, but the thus obtained solutions are of'a most toxic effect to the organism of mammals. I

We also know the method of dissolving the emcient ingredients of the derris-root and of thepyrethrum in acetone. Those solutions, however, cannot be worked with aliphatic hydrocarbons into the usual spraying means, as they dont last for a long time and the efficient ingredients, e. g. those of the derris-root begin soon to precipitate. On the other hand, the solubility of the rotenone in aliphatic ketones is notsufflcient to allow the manufacture of lasting preparations good for the purpose. 7

Now it has been vfou'nd that it is quite easy to produce clear and lasting solutions of the rotenone, its derivatives and particularly of di-hydrorotenone, pyrethrineapyrethrum and derris-rootextracts in petroleum-distillates (kerosene), if for the dissolving of the rotenone, etc., one makes use of cyclic ketones such as cyclo-pentanone, cyclo-hexanone or methyl-cyclo-hexanone,

dekalinone and the like, to which partly or entirely hydrogenized cyclic hydrocarbons may be added. The hydrogenation-products of the naphthalene, e. g. the tetrahydroand the deka- S hydro-naphthalene, have proved particularly apt for the purpose.

Furthermore it has been found that the solutions of the rotenone, of its derivatives, of derris root-extracts, of the pyrethrins or of the pyrethrum-extracts in cyclic ketones and hydrogenized aromatic hydrocarbons, are likewise fit for the use in an aqueous solution, if a neutral emulsifying agent of high efliciency is admixed. Emulsifying agents of a particular fitness are the sulfonating-products of the fatty alcohols and especially those with 8 to 10 C-atoms, highly sulfonated Turkey-red oils and the like. These solutions, when diluted with water, form good stable emulsions from which the efllcient ingredients, which are 'colloidally distributed, precipitate very slowly in comparison with those containing'merely a water-soluble solvent and a wetting-out agent. I

The hydrogenized aromatic hydrocarbons distinguish themselvesalso compared with the usual solvents such as chloroform and benzeneby a lesser poisonous action and they'dont possess any of the properties damaging the plants.

Example 1 In dissolving 0.5 g. of a 100%-rotenone (163 F) in 10 cm. of cyclohexanone (bearing 85% of ketone) and in adding 90 cm. of kerosene or a mixture of 10 cm. of tetra-hydroand 10 of deka-hydro-naphthalene, the rotenone will crystllize out after some time; but by the addition of a solution of 0.5 g. of rotenone in 10 cm. of

cyclohexanone (85%), 10 cm. of tetrahydro- 'naphthalene, 20 cm. of dekahydronaphthalene and -80 cm. of kerosene, one obtains a liquid which also after a long standing remains clear and which is very suitable for the combating of flies and gnats.

' Example 2 'Indissolving 0.5 g. of rotenone in 10 cm. of cyclohexanone and 10 cm. of delta-hydronaphthalene and in adding 30 g. of an aqueous 30%-solution of the sodium salts of the sulfuric acid esters of fatty alcohols with 8-10 C-atoms, one obtains a lasting, clear and transparent solution which, when diluted with water, is particularly flt for the combating of gadfly-grubs with pasture-animals. The dilution made with water and wherein the rotenone is fine-suspended, has a milky-turbid aspect and it scarcely precipitates. This diluted solution is also an excellent means to combate the horticulture-damaging pests and doesnt do any harm to the plants.

Di-hydro-rotenone, derris-extracts, pyrethrins and pyrethrum-extracts allow, in observing the above prescriptions, of being dissolved in quite the same way. a

RICHARD NEU. 

